Besides what mauserme said about pausing standard shield, but it looks like this was picked up by the web shield provider and not standard shield, given that the file location is a URL, so you would need to pause the web shield also.
Assuming you do that the panda on-line scanner dumps this junk in the system folders and this makes it more difficult to get rid of and the avast on-demand scan is likely to pick it up on a scan in the future. If you remove the active scan folder that it creates for the unencrypted signature files, it could end up as a restore point and avast would find it there also.
You are by now probably getting the idea that I don't much care for the panda on-line scanner and you would be right when there are others that don't do this. On-line Virus Scanners and other useful Links
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